7/2/2019 12:20 AM PT

28-year-old Griner is openly gay -- she's engaged to longtime girlfriend Cherelle Watson -- and knows first hand how tough it can be to come out when you're a big star under the microscope.

But, the 5-time WNBA All-Star says she's especially impressed with the "Old Town Road" artist for not letting homophobes and negative gay stereotypes (especially in the hip-hop world) stop him from going public about his sexuality.

"I just think it's awesome he did that," Griner says ... "takes a lot of bravery."

Griner says it's 2019 and people should be able to love who they want to love and be who they want to be without fear of a backlash ... and she thinks Lil Nas X is helping to achieve that goal.

"I think it's real big ... kudos to him."

Lil Nas X came out via a social media post on June 30 -- the last day of Gay Pride month -- and we're told he was inspired to do so after such a positive experience performing at the Glastonbury Music Festival in England, which is known for its inclusivity.